Bayer MaterialScience AG is to take part in Simac 2006, which will be held in the Bologna exhibition centre from April 19-22. Hall 35, stand A31-B28, will showcase the group’s wide range of polyurethane raw materials and services for the shoe industry. Centre stage will be taken by new classes of materials and innovative technologies from the performance-proven Bayflex Footwear brand, which brings together the company’s diverse range of raw materials for polyurethane shoe soles. This broad range of systems comprises Bayflex Safety for safety shoes, Bayflex Active for sports and leisure shoes, Bayflex Fashion for fashion shoes, and Bayflex Basics for basic raw materials. ‘These systems enable foamed shoe soles to be made with densities of between 200 and 1,200kg/m3‘, says Dr Eva Emmrich, shoe technology expert at Bayer MaterialScience.

In order for safety shoes to satisfy the numerous demands placed on them, they need to be robust and abrasion resistant. This is particularly important for the soles, which must also be extremely resistant to chemicals and solvents. Bayflex Safety is a polyurethane system that meets all of these requirements with ease. A two-layer construction provides the sole with remarkable strength and durability. Moreover, it is possible to build in additional functionality such as ESD (electrostatic discharge) protection, which is important in the automotive industry, in microchip manufacturing and hospitals.

Durability is of key importance in the Bayflex Active Lightweight product range for sports and leisure shoes too. The range also boasts impressively lightweight foamed soles, thanks to the success of developers at Bayer MaterialScience in further reducing foam density. Shoes with midsoles made in this way offer outstanding comfort, because the polyurethane material provides excellent shock absorption, good resilience and balanced energy absorption. As a result, the energy absorption and distribution of the material offers optimum support to the movement of the foot, thereby eliminating fatigue during running and walking, which is a vital performance characteristic for sports shoes.

In contrast, manufacturers of fashion shoes must be able to react quickly to new trends. It is particularly important that high-quality customised surfaces can be produced. Bayflex Fashion systems based on polyether polyurethanes are especially suitable in this case, as they enable accurate reproduction of mold detail.

Broad range for insoles

Bayflex Fashion polyether systems enable an incredibly diverse range of applications for lightweight insoles and shoe inserts. The products offer a large degree of freedom in tailoring soles to individual feet. ‘Elasticity can be set within broad limits, from elastic to viscoelastic, and quite different hardnesses and energy absorption settings can be achieved. Excellent durability, as evidenced by the low static fatigue, great toughness and outstanding tear resistance, are also advantages’, says Dr Eva Emmrich. Moreover, exceptional resistance to humid aging and microbes is particularly important, and if required insoles can also be treated with a fungicide to prevent athlete’s foot.

Another advantage is that Bayflex Fashion can be used for in-shoe components, where low material weight is important alongside strength and quality. Even under heavy loads, there is no compression of the heel edges. Last but not least, insoles and in-shoe components can be produced efficiently and with short demold times using the casting process.